`assert_matches!` output could be more consistent with `std::assert_matches!`

[xtqqczze]

The failure output from assertables::assert_matches! could be clearer.

Current output:

assertion failed: `assert_matches!(a)`
https://docs.rs/assertables/10.1.0/assertables/macro.assert_matches.html

This crate could perhaps be more consistent with std::assert_matches! in Rust 1.96, which uses output along the lines of:

assertion `left matches right` failed

[joelparkerhenderson]

The failure output from assertables::assert_matches! could be clearer.

What would make the output clearer for you, separate from the consistency aspect?

assertion left matches right failed

When I talk with developers, most of them like having the link to the documentation.

The notable exceptions are 1. developers who generate a lot of assertion failures in CI/CD who prefer shorter messages, 2. developers who work locally and want colorful ouput such as via pretty assertions, 3. developers who prefer structured default messages such as JSON output.